Steam-engine.



No. 882,635. PATENTED OCT. 9, 1906.

LA. SVENSON.

STEAM ENGINE.

APPLICATION FILED mnza, 1904.

2 SHEETS-SHEET 1.

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" PATENTED 0019, 1906.

J. A. SVENSON.

1 STEAM ENGINE. APPLIOATION FILED MAY25, 1904.

2 SHEETSSHEET 2- W itl'orizey.

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JOHN A. svENsoNfoF PITTSBURG, PENNSYLVANIA.

STEAM-ENGINE.

Specification of Letters Patent.

Patented Oct. 9, 1906.

Application filed May 25, 1904:- Serial No. 209,758-

To all whom it may concern:

Be it known that I, JOHN A. SvENsoN, ai citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new;

and useful Improvements in Steam-Engines,

valve mechamsm to be hereinafter escrlbed.

of Which the following is a specification.

This invention relates to high-speed steamengines of the reciprocating type, and has for:

one of its objects the reduction in number Q of any suitable form and number.

and weight of the reciprocating parts.

Another object of the invention is the prevention of pounding in the reciprocatingv parts.

A further object is the production of means for lessening heat wastes.

The invention further relates to the various improvements in detail hereinafter more fully set forth.

In the attainment of these objects I have produced an engine comprising two single-- acting cylinders, the distribution of steam to and from said cylinders being controlled by a rotary valve mechanism and the piston in one of said cylinders being provided with an This elastic cushion may elastic cushion. consist of steam, and in such case the steamcushion also acts to prevent cylinder condensation. In the construction herein shown and described the steam forming this elastic cushion is in direct contact with one side of the piston and with the interior walls of the cylinder, thus fulfilling its function of jacketing more efficiently than the ordinary form of steam-jacket, wherein the steam contacts only the outside walls of the cylinder.

While I have herein shown an engine of the vertical compound type, my invention is not limited thereto, but may be applied to horizontal and to simple engines.

In the accompanying drawings, Figure 1 is .u. vertical central section through an engine embodying the features of my invention. Fig. 2 is a top planview of the high-pressure cylinder and the partition between it and the low-pressure cylinder. Fig. 3 is a top plan view of the cut-off valve, together with its actuating mechanism. Fig. 4 is a side view of the mechanism shown in the last preceding figure. Fig. 5 is an under side view of the main valve. Figs. 6, 7, 8, 9, and 10 illustrate the action of the valves in effecting the passage of steam into and out of the cyliners.

In the drawings, A and B are two steamstuffing-box is, formed in the partition u.

longitudinal axis. A partition-Wall it closes the adjacent inner ends of the cylinders, the outer ends thereof being open. The partition-wall u is extended beyond the peripheries of the cylinders A and B to su port the Into the cylinders A and B are fitted pistons a and C, respectively, said pistons being provided with peripheral packing-rings b and c The two pistons are rigidly connected together by means of the piston-rod d passing throughra o the lower piston C is pivoted a connectingrod 6, which in turn is connected with a crankshaft f, rotatably mounted in bearings o and having fixed thereto a fiy-wheel h.

At the closed end of cylinder A, I provide a number of steam-ports m, communicating with the interior of said cylinder and the upper side of the partition u. A similar number of steam-ports n, extending through the partition a, open into the cylinder B. These ports m and n are grouped in two rows concentric with the axis of the cylinders A and B. The number and relative location of the ports m and n may be varied to suit the relative sizes of the cylinders.

A main valve H in ring form is rotatably mounted upon the cylinder A, being slidably supported upon the upper side of the partition a. Its outer perip ery is provided with gear-teeth which mesh with the teeth of a spur-pinion K. The latter is mounted ona vertical shaft L, having suitable bearings in a casing U, formed integral with the partitionwall a and in the housing 1 and to its lower end is keyed a gear-wheel M, adapted to mesh with a gear-wheel M, secured to the crankshaft f. A rotary motion is thus imparted to the main valve H during the operation of the engine. The train of gearing just described is so proportioned that the crankshaft shall make as many revolutions to one of the valve as there are steam-ports ineach cylinder. Thus if there are twelve ports leading into the high-pressure cylinder and a similar number admitting steam to the lowpressure cylinder the valve H makes one revolution to twelve of the crank-shaft. The casing U incloses the main valve H and the spur-pinion K, said casing having formed therein a circular channel U, in which the rim of the valve H lies and which is adapted cylinders placed close together upon the same duced and withdrawn.

A circular channel V, formed in the casing U, is adapted to receive the exhaust-steam issuing from the radial ports 0 in the main valve H, which ports 0 are adapted to register with the ports n in the partition M. An

exhaust-pipe F communicates with said ex.

haust-channel V and the atmosphere or a condenser. A circular series of inlet-ports g, extending through the main valve H, is adapted to register with the series of ports 'm in the partition '11,. Ports 1), formed in the under face of the main valve II, are adapted to register with the ports m and n in said partition, and thus permit the passage of steam from the high-pressure cylinder A to the low-pressure cylinder B.

A cut-off valve I in ring form is supported upon the main valve H. This cut-ofi valve has ports i, which in number and location correspond with 'the ports g, piercing the main valve H. The cut-off valve does not rotate like the main valve, but may be given a slight oscillatory movement on its longitudinal axis by means of teeth n, formed at one side of said cut-off valve, which teeth are adapted to be engaged by a gear-segment N,

secured to a shaft P, which in turn is actuated by means of an arm R.

T is a suitable bearing for the outer end-of the shaft P.

' The upper end R of the arm R is connected with a regulating device (not shown) of common constructionas, for example, a fly-ball A steam-chest G, formed in a casting d, surrounds the cylinder A and has at a suitable point an opening G, communicating with the steam-inlet pipe E. Packing-rings s 8 make a steam-tight joint between the main valve H and the steam-chest G.

I inclose the upper part of the cylinder A in a casing b, which, in conjunction with the steam-chest G and the walls of cylinder A and the piston 0, forms a gas-tight chamber D, into which I admit some suitable gas through the inlet-pipe y. At the lowest part of the chamber D, I provide a drainagepipe 2. The pipes y and z are controlled by means of sultable valves. (Not shown.) The gas admitted into the chamber D and entrapped therein through the closing of pipes y and 2 becomes alternately expanded and compressed by the movement of piston a, and the varying pressure thus opposed to the upward movement of said piston may be so adjusted as to practically neutralize all forces acting in an upward direction along the piston-rod d and connecting-rod 6. Hence in operation pressure is exerted on one side only of the crank-shaft, crank-pin, and wrist-pin bearings. Since there is no change of working contact in said bearings, disastrous pounding is prevented.

When steam is to be used for cushioning purposes, the inlet-pipe y communicates with the boiler, and a certain minimum pressure is maintained in the chamber D. The minimum pressure in the chamber D may be varied according to the speed at which the engine is to be run, a high speed requiring a greater cushioning pressure than a lower speed. On the average, a pressure equal to at least one-half of the boiler-pressure is required at the beginning of the upstroke to do the work of cushioning at high speed. In order to prevent pounding in the bearings, sufficient cushioning pressure is provided to counteract all the momentum forces in addition to the expansive force of the steam admitted t the under side of the piston a, so that no steam-pressure whatever and no force due to momentum shall act on the crankpin at any time in an upward direction. In fact, the cushioning pressure should be slightly greater than the resultant of all upwardly-acting forces in order to have some pressure to meet the crank-pin at all times during the upstroke, and thus to insure that there shall be no change of working contact in the bearings. It will thus be seen that while my machine is double actingthat is, while the steam in the cylinders A and B tends to push the crank-pin up as well as downyet the cushion counterbalances the force of the steam exerted in one direction and makes the engine, in effect, single acting.

A varying pressure in the gas-chamber D is advantageous, as it more correctly balances the upward forces, which forces appear in a progressively increasing amount toward the end of the upward stroke when certain speeds are attained, due to the momentum of the reciprocating parts. The elastic force exerted against the top of piston a is determined by the initial pressure of the gas and the size of the chamber D. 7

Any suitable gas may be employed in the chamber D; but I prefer-to use steam, in which case it serves as a steam-jacket for the cylinder A. It will be seen that the steam is in contact with the upper side of the piston or and the inner walls of the cylinder A, and thus performs its office of jacketing and re heating more efficiently than if it merely surrounded the cylinder.

c and e are suitable casings surrounding the cylinders A and B and the chamber D to prevent radiation of heat and to give the structure a neat appearance.

I prefer to make the housing 1' in the form of a closed casing, adapted to contain a quantity of lubricating-oil. During the working of the engine the oil is thrown in all directions, thereby subjecting all the moving parts in said casing to an oil-bath, insuring thorough lubrication. It will be noticed pistons a and C occupy their lowermost position, the operation of the valve mechanism is as follows, reference being had to Figs. 6, 7, 8, 9, and 10. The ports q of the main valve H have just uncovered the ports m and steam enters the cylinder A from the steam- The cut-off valve I stands in the position shown by Fig. 7 to open the ports 9 almost to the full extent.

At the same time the ports a have just 'opened to permit the escape into the cavity V of the steam that during the previous; stroke had performed work in the low-pressure cylinder B. As the pistons move upward, impelled by the steam entering cylin- 1 der A and by the momentum of the flywheel h, the main valve H also continues to rotate. When the pistons reach the position at half-stroke, the valve H has arrived at the point indicatedin Figs. 8 and 9. and 0 now coincide with m and n and the ex haust-steam from cylinder B issues freely,

- but the supply to cylinder A has just been arrested by the cut-off valve I, as shown in Fig. 9. As before stated, the cut-off valve is normally stationary, and the closing of.

ports (1 in the main valve H is due to their movement past the ports i in said cut-off valve; Should the regulating device which controls the cut-off valve I be actuated by a variation in the speed of the engine, it will cause said valve I to take another position, thereby cutting off the steam-supply earlier or later than half-stroke- The steam admission may range over the entire stroke in other words, from nothing to full stroke. The top of the stroke being reached, the main valve H occupies the position shown in Fig. 10, and the ports m and n are now about to be placed in communication, one with the other, through'the ports 19 in said main valve. As soon as this occurs partiallyexpanded steam from cylinder A passes into low-pressure cylinder B, where its expansion is carried still farther. During the downward stroke the flow of steam from cylinder A to cylinder B takes place, as indicated in Fig. 1, on the right-hand side and continues practically without interruption to the end of the stroke. The downward stroke having been completed, the cycle just described is repeated.

My invention is not restricted to the precise construction and arrangement of parts herein shown and described, as such construction and arrangement may be modified or varied by those skilled in the art without departing from the spirit and scope of my in- I vention.

Ports (1 gle-acting cylinders arranged to act in oppo- ,site directions; a piston in each of said cylinders, said pistons being arranged to move together; means for introducing steam into one of said cylinders; means for introducing the exhaust from said cylinder into the other cylinder; and means for providing an elastic cushion for one of said pistons adapted to exert a pressure on said piston at all times.

2. In a steam-engine, in combination, two single-acting cylinders arranged to act in op. posite directions; a piston for each of said cylinders arranged to move together; steam admission and exhaust means for said cylinders; and means for substantially neutralizing the expansive force of the steam admitted to the cylinder of one of said pistons,

saidmeans comprising means for forming an elastic cushion adapted to exert a pressure on said piston at all times.

3. In a steam-engine, in combination, two single-acting cylinders arranged to act in opposite directions; a piston in each of said cylinders, said pistons being arranged to move together; and a closed chamber communicat ing with the interior of one of said cylinders and. adapted to contain a gas for forming an elastic cushion for the piston in said cylinder.

4. In a steam-engine, in combination, two single-acting cylinders arranged to act in opposite directions; a piston in each of said cylinders, said pistons being arranged to move together; means for introducing steam into one of said cylinders; means for introducing the exhaust from said cylinder into the other cylinder; and a closed chamber communicating with the interior of one of said cylinders and adapted to contain a gas for forming an elastic cushion for the piston in said cylinder 5. In a steam-engine, in combination, two

alined single-acting cylinders; a piston in each of said cylinders, said pistons being rigidly connected together; and a closed chamber communicating with the interior of one of said cylinders and adapted to contain a gas for forming an elastic cushion for the piston in said cylinder.

6. In a steam-engine, in combination, two alined single-acting cylinders; a piston in each of said cylinders, said pistons being connected rigidly together; means for introducing steam into one of said cylinders; means for introducing the exhaust from said cylinder into the other cylinder; and a closed chamber communicating with the interior of one of said cylinders and adapted to contain a gas.

7. In a steam-engine, in combination, two single-acting cylinders arranged to act in opposite directions, one of said cylinders having an open end; a piston in each of said cylinders, said pistons being arranged to move together; and a closed chamber communicating with the open end of one of said cylinders and adapted to contain steam.

- vice for said cylinder comprising a closed chamber arranged about and communicating at all times with the open end of said cylinder, and means for supplying steam to said chamber.

9. In a steam-engine, in combination, two single-acting cylinders placed end to end and having a partition extending between and constituting their adjacent closed ends, said partition having steam admission and exhaust ports therein for both cylinders; a rotary valve-ring surrounding one of said cyl-.

inders and contacting said partition, said valve-ring having ports therein adapted to coincide with the ports in said partition; and means for rotating said valve-ring.

10. In a steam-engine, in combination, a high-pressure cylinder having a steam-port therein; a low-pressure cylinder also having a steam-port therein; a piston in each of said cylinders a valve member having ports therein adapted to be placed in-communication with the steam-port in said high-pressure cylinder, some of said ports communicating with the steam-supply and others of said ports being adapted to be placed in communication with the steam-port'in said lowpressure cylinder; and means for rotating said valve member.

11. In a steam-engine, in combination, a high-pressure cylinder having a steam-port therein; a low-pressure cylinder also having a steam-port therein; a piston in each of said cylinders; a valve-ring rotatably mounted concentric with one of said cylinders, said valve-ring having ports therein adapted to be placed in communication with the steamport in said high-pressure cylinder, some of said ports communicating with the steamsupply' and others of saidports being adapted to be placed in communication with the steam-port in said low-pressure cylinder; and means for rotating said valve member.

12. In a steam-engine, in combination, a high-pressure cylinder having a steam-port therein; a low-pressure cylinder also having a cylinder in communication with the exhaust;

and means for rotating said valve member.

13. In a steam-engine, in combination, a high-pressure cylinder and a low-pressure cylinder placed end to end, said cylinders being provided with steam-ports; a piston for each of said cylinders; a rotary valve having ports therein arranged to be placed in comcidence with the cylinder-ports for placing said cylinders in communication with each other, and for placing the low-pressure cylinder in communication with the exhaust; and means for rotating said valve.

14. In a steam-engine, in combination, a high-pressure cylinder and a low-pressure cylinder placed end to end, said cylinders being provided with steam-ports; a piston for each of said cylinders; a partition between said cylinders; a rotary valve seated on said partition and having ports arranged to be placed in coincidence with the cylinder-ports for placing said cylinders in communication with each other, and for placing the lowpressure cylinder in communication with the exhaust; and means for rotating said valve.

15? In a steam-engine, in combination, a cylinder; a piston in said cylinder; a rotary valve for controlling the passage of steam into and out of said cylinder, said valve supporting an annular series of gear-teeth; a

grooved member adapted to contain oil in which said teeth are arranged to run; a pinion arranged to mesh with said gear-teeth; and an operative connection between said piston and said pinion for rotating the latter.

- JOHN A. SVENSON. Witnesses:

SAMUEL MIDDLETON, B. F. RICHARDS. 

